HIV which is a causative agent for acquired immune deficiency syndromes (usually called AIDS) is a retro virus, and to discover such a chemical compound or substance which can inhibit the reverse transcriptase of HIV is considered to be one of the targets for the discovery of an anti-HIV substance. Adriamycin and other certain compounds have already been known to inhibit the reverse transcriptase of fowl leukemia virus {"Journal of Antibiotics" 40, 396-399 (1987)}, but they can exhibit high toxicity. There is thus a strong demand for the preparation and development of a novel adriamycin derivative which has a high inhibitory activity against the reverse transcriptase of HIV but shows a low cytotoxicity.
We, the present inventors, have carried out an investigation so as to meet the above-described demand. We have synthetically prepared a variety of anthracycline derivatives by using the hydrobromide or hydrochloride of 14-bromodaunomycin (Belgian Patent No. 731398 issued at Oct. 13, 1969) or 14-chlorodaunomycin (Japanese Patent Application No. 173924/87, U.S. application Ser. No. 07/ 204,363; European patent application No. 88305309.2) as a starting material. As a result, we have succeeded in preparing such 14-O-acyladriamycin derivatives represented by the under-mentioned general formula (I). Moreover, it has also been found that these novel compounds have strong inhibitory activity against the reverse transcriptase of HIV and are of low cytotoxicity, leading to completion of this invention.